A chemical catalyst is a substance that lowers the required activation energy of a reaction. The activation energy is the amount of energy required to activate or start a pr â¦ ocess, this can be in the form of many things, such as heat. catalyst accelerates the process of a chemical reaction. If a reaction is a slow one then by introducing a catalyst would speeden up the process. For example :- The reaction â¦ between hydrogen and nitrogen to create ammonia is a slow reaction. Finely divided iron act as a catalyst.
For other uses, see Boatswain (disambiguation). A boatswain (/ËboÊsÉn/, formerly and dialectally also /ËboÊtsweÉªn/), bo's'n, bos'n, or bosun, also known as a Petty Officer or a qualified member of the deck department, is the seniormost rate of the deck department and is responsible for the components of a ship's hull.
Aviation boatswain's mates play a major part in launching and recovering naval aircraft quickly and safely from land or ships. This includes aircraft fuelling and fuel systems. Later in their careers ABFs can earn the advanced AB rating that requires supervision of all these individual specialties.